SirRandalMac Donnell, 1st Marquess of Antrim was born in 1609.1 He was the son of Randal Mac SorleyMac Donnell, 1st Earl of Antrim and AliceO'Neill.1 He and LadyLucyHamilton were engaged before 1627 but after refusing to go ahead with the marriage, he was ordered to pay £3000 to the lady.1 He married, firstly, CatherineManners, Baroness de Ros of Helmsley, daughter of FrancisManners, 6th Earl of Rutland and FrancesKnyvett, before 12 April 1635.2 He married, secondly, RoseO'Neill, daughter of SirHenryO'Neill and MarthaStafford, before 20 March 1655/56.1 He died on 3 February 1682, without issue.2,1 He was buried at BonamargyG.1 He succeeded as the 2nd Earl of Antrim [I., 1620] on 10 December 1636.1 He succeeded as the 2nd Viscount Dunluce, co. Antrim [I., 1618] on 10 December 1636.1 He was appointed Knight on 17 March 1638/39 at Dublin, County Dublin, IrelandG, by the Lord Deputy Wentworth.1 In 1640 He exerted himself greatly in the Royal cause.1 He was created 1st Marquess of Antrim [Ireland] on 26 January 1644/45.1 He undertook to raise an army in Ireland, and to transport it to Scotland in the King's cause, believing that "all the clans of the Mac Donnells in the Highlands might be persuaded to follow him."1 In August 1651 he was "quartered by the rebels not far from Kilkenny in a very obscure and regarded condition" and apparently then opposed to the Loyalists, but, writes Lord Clanricarde, "I apprehend little danger from him unless he find a contrivement to appear for his Majesty, having gained the reputation of pulling down the side he is on."1 After December 1660 he was a prisoner in the Tower for some months over a charge of treasonable correspondence with the Confederate Roman Catholic Irish during 1640-1645.1 Clarendon describe him as a handsome man, very extravagent 'of excessive pride and vanity, and of a marvellously weak and narrow understanding.1' On his death, the Marquessate of Antrim became extinct.1